Commensurate and Incommensurate Phases in the SystemA4A′Ir2O9(A=Sr, Ba;A′=Cu, Zn)

Crystal growth, structure determination and magnetism of a new m=3, n=1 member of the A3n+3mA′nB3m+nO9m+6n family of oxides: 12R-Ba12Rh9.25Ir1.75O33

“…Iridium and rhodium are located on both ''trigonal prismatic'' and octahedral sites. Selected interatomic distances are located in Table 3; the M-O distances are consistent with others reported in literature [23,27]. The M-M distances range from 2.49 Å in the middle of the sequence to 2.90 Å for distances between the ''trigonal prism'' and its nearest neighbor octahedron, giving rise to a V-shaped Rh(Ir)-Rh(Ir) distance vs. chain-position plot as shown in Fig.…”

“…In addition, an ever increasing number of examples of other structures, including Sr 6 Rh 5 O 15 (n ¼ 1; m ¼ 1) [23,24], Ba 8 CoRh 6 O 21 (n ¼ 3; m ¼ 5) [25], Ba 9 Rh 8 O 24 (n ¼ 1; m ¼ 2) [26], Sr 4 CuIr 2 O 9 (n ¼ 3; m ¼ 1) [27], and Ba 5 PdMn 3 O 12 (n ¼ 3; m ¼ 2) [28] have been prepared as both powders and in single-crystal form.…”

Sr3NiRhO6 and Sr3CuRhO6—Two New One-Dimensional Oxides. Magnetic Behavior as a Function of Structure: Commensurate vs Incommensurate

“…The results are only qualitative and not quantitative in nature, since a reasonable endpoint was not observed. Other members of this family have also displayed such a poorly de"ned endpoint in the TGA data (18,38). Qualitatively, the weight loss for the nickel phase was 10.0%, corresponding to an oxygen content of 6.3, and 9.9% for the copper phase, corresponding to an oxygen content of 6.3.…”

“…5 and 6, respectively. They cannot be indexed using a conventional 3D cell; however, the patterns can be fully indexed using four indices (hklm), implementing a similar method as shown for other incommensurate compounds (1,15,18) 0.6716 and 0.6824, for the nickel and the copper compounds, respectively, compared to a theoretical value for the commensurate m"0, n"1 structure of 0.75. A smaller experimental c /c value compared to the theoretical value indicates that some of the trigonal prisms have been converted to octahedra and that the structure no longer strictly contains alternating octahedra and trigonal prisms along the polyhedral chain.…”

Crystal growth of new strontium iron rhodium oxides: Sr4Fe0.73Rh2.27O9 and SrFe0.71Rh0.29O3

“…The structure consists of chains containing two face-sharing octahedra separated by one face-sharing trigonal prism. Other m = 1, n = 3 members of this family are known and include Sr 4 CuIr 2 O 9 [20], Sr 4 ZnIr 2 O 9 [20], Sr 0.5 Ca 0.5 Co 3 O 9 , Sr 4 Ni 3 O 9 , [21], Sr 4 Mn 2 NiO 9 [8], Sr 4 Mn 2 CuO 9 [22], Ba 4 CuIr 2 O 9 [20], Ba 4 ZnIr 2 O 9 [20], Ba 4 CuPt 2 O 9 [23] and Ba 4 Pt 3 O 9 [24] as well as some cation deficient compositions, Sr 4 Ru 2 O 9 [25] and Sr 4 Ni 2.5 O 9 [26]. During the process of trying to grow rhodium-rich strontium iron rhodium oxide single crystals, we also synthesized SrFe 0.71 Rh 0.29 O 3 , a cubic perovskite containing iron and rhodium in the +4 oxidation state.…”